Working machine

ABSTRACT

A working machine body includes a machine body having a front and a rear opposite to the front in a front-rear direction and an engine mounted in the machine body. A selective catalytic reduction catalyst is provided in the machine body and connected to the machine body and connected to the engine. A urea aqueous solution tank is to store a urea aqueous solution. The urea aqueous solution tank is connected to the selective catalytic reduction catalyst and provided in the machine body between the engine and the front of the machine body in the front-rear direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of the U.S. patentapplication Ser. No. 15/084,489, filed Mar. 30, 2016, which claimspriority under 35 U. S. C. § 119 to Japanese Patent Application No.2015-069937, filed Mar. 30, 2015, entitled “Working Machine”, JapanesePatent Application No. 2015-069938, filed Mar. 30, 2015, entitled“Working Machine”, and Japanese Patent Application No. 2015-069939,filed Mar. 30, 2015, entitled “Working Machine”. The contents of theseapplications are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a working machine.

Discussion of the Background

JP 2010-59681 A discloses a working machine which includes a machinebody, a boom provided on the side of the machine body, and a lift linkpivotally supported on a rear part of the boom.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a working machineincludes a machine body, a right traveling device, a left travelingdevice, a boom, an engine, a selective catalytic reduction catalyst, anda urea aqueous solution tank. The machine body has a front and a rearopposite to the front in a front-rear direction of the working machineand having a right side and a left side opposite to the right side in aright-left direction perpendicular to the front-rear direction. Theright traveling device is arranged on the right side of the machinebody. The left traveling device arranged on the left side of the machinebody. The boom has a boom front and a boom rear opposite to the boomfront in the front-rear direction. The boom rear is rotatably supportedat the rear of the machine body. The boom front is to be connected to aworking tool. The engine is mounted in the machine body. The selectivecatalytic reduction catalyst is provided in the machine body andconnected to the engine. The urea aqueous solution tank is to store aurea aqueous solution. The urea aqueous solution tank is connected tothe selective catalytic reduction catalyst and provided in the machinebody between the engine and the front of the machine body in thefront-rear direction.

BRIEF DESCRIPTION OF DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein

FIG. 1 is a side view of a rear part of a machine body according to afirst embodiment;

FIG. 2 is a sectional side view of an installment portion of a ureaaqueous solution tank according to the first embodiment;

FIG. 3 is a sectional back view of the installment portion of the ureaaqueous solution tank according to the first embodiment;

FIG. 4 is a sectional plan view of the installment portion of the ureaaqueous solution tank according to the first embodiment;

FIG. 5 is a perspective view of the machine body according to the firstembodiment;

FIG. 6 is a perspective view of a support frame in a state where anouter wall is detached according to the first embodiment;

FIG. 7 is an exploded perspective view of the support frame in whichpart of the support frame is omitted according to the first embodiment;

FIG. 8 is a perspective view of a rear part of the support frame on theinner surface side according to the first embodiment;

FIG. 9 is a side view of an interior of the machine body according tothe first embodiment;

FIG. 10 is a plan view of the interior of the machine body according tothe first embodiment;

FIG. 11 is a side view of a working machine according to the firstembodiment;

FIG. 12 is a plan view of the working machine according to the firstembodiment;

FIG. 13 is a front view of the working machine according to the firstembodiment;

FIG. 14 is a side view of the working machine including wheel typetraveling devices according to one variation of the first embodiment;

FIG. 15 is a schematic side view of an interior of a machine bodyaccording to a second embodiment;

FIG. 16 is a schematic plan view of the interior of the machine bodyshowing the second embodiment;

FIG. 17 is a perspective view of the machine body according to thesecond embodiment;

FIG. 18 is a side view of a working machine according to the secondembodiment;

FIG. 19 is a plan view of the working machine according to the secondembodiment;

FIG. 20 is a front view of the working machine according to the secondembodiment;

FIG. 21 is a schematic side view of an interior of a machine bodyshowing a third embodiment;

FIG. 22 is a schematic plan view of the interior of the machine bodyshowing the third embodiment;

FIG. 23 is a schematic side view of an interior of a machine bodyshowing a fourth embodiment;

FIG. 24 is a schematic plan view of the interior of the machine bodyshowing the fourth embodiment;

FIG. 25 is a schematic side view of an interior of a machine bodyshowing a fifth embodiment;

FIG. 26 is a schematic plan view of the interior of the machine bodyshowing the fifth embodiment;

FIG. 27 is a schematic side view of an interior of a machine bodyshowing a sixth embodiment;

FIG. 28 is a schematic plan view of the interior of the machine bodyshowing the sixth embodiment;

FIG. 29 is a side view of the working machine including wheel typetraveling devices according to one variation of the second embodiment;

FIG. 30 is a side view showing a working machine having no lift linksaccording to another variation of the first to sixth embodiments;

FIG. 31 is a side view showing another working machine having no liftlinks according to still another variation of the first to sixthembodiments;

FIG. 32 is a schematic sectional side view of a working machineaccording to further variation of the first to sixth embodiments; and

FIG. 33 is a sectional plan view of an installment portion according tothe further variation of the first to sixth embodiments.

DESCRIPTION OF THE EMBODIMENTS

The embodiments will now be described with reference to the accompanyingdrawings, wherein like reference numerals designate corresponding oridentical elements throughout the various drawings.

First Embodiment

Hereinafter, a first embodiment of a working machine according to thefirst embodiment of the present invention will be described withreference to the drawings.

FIG. 11 shows a side view of a working machine 1 according to the firstembodiment of the present invention. FIG. 12 shows a plan view of theworking machine 1. FIG. 13 shows a front view of the working machine 1.

In FIGS. 11 to 13, a compact track loader is shown as one example of theworking machine 1. However, the working machine 1 according to the firstembodiment of the present invention is not limited to the compact trackloader but may be other types of working machines such as a skid-steerloader.

The working machine 1 includes a machine body (vehicle body) 2, a cabin3, working devices 4, and traveling devices 5. The cabin 3 is mounted inthe machine body 2 on the front part side. In this cabin 3, a driver'sseat 6 is provided.

It should be noted that in the first embodiment of the presentinvention, the front side of a driver seated in the driver's seat 6 ofthe working machine 1 (left side of FIG. 11) will be referred to as thefront side, the rear side of the driver (right side of FIG. 11) will bereferred to as the rear side, the left side of the driver (near side ofFIG. 11) will be referred to as the left side, and the right side of thedriver (far side of FIG. 11) will be referred to as the right side inthe following description.

The horizontal direction orthogonal to the front and rear direction(front-rear direction) will be referred to as the machine body widthdirection (right-left direction) in the following description. As shownin FIG. 13, the side away from a center part of the machine body 2 andclose to a right part or a left part will be referred to as the machinebody outer side in the following description. In other words, themachine body outer side indicates the side away from the machine body 2in the machine body width direction. The opposite side to the machinebody outer side will be referred to as the machine body inner side inthe following description. In other words, the machine body inner sideindicates the side close to the machine body 2 in the machine body widthdirection.

As shown in FIG. 5, the machine body 2 has a right side frame portion 8,a left side frame portion 9, a front frame portion 10, a bottom frameportion 11, and an upper frame portion 12. The right side frame portion8, the left side frame portion 9, the front frame portion 10, the bottomframe portion 11, and the upper frame portion 12 are formed by combiningplate materials.

The right side frame portion 8 forms the right part of the machine body2. The left side frame portion 9 forms the left part of the machine body2. The front frame portion 10 forms a front part of the machine body 2,and couples front parts of the right side frame portion 8 and the leftside frame portion 9. The bottom frame portion 11 forms a bottom part ofthe machine body 2, and couples lower parts of the right side frameportion 8 and the left side frame portion 9. The upper frame portion 12forms a rear upper part of the machine body 2, and couples rear upperparts of the right side frame portion 8 and the left side frame portion9.

Hereinafter, the right side frame portion 8 and the left side frameportion 9 will be described. However, since the right side frame portion8 and the left side frame portion 9 have the substantially sameconfigurations, the side frame portions 8, 9 will be described withreference to the left side frame portion 9 in the first embodiment.

As shown in FIG. 5, each of the side frame portions 8, 9 has a mainframe 13, a track frame (a traveling device support body) 14, a motorattachment portion 15, and a support frame 16.

As shown in FIG. 7, the main frame 13 is arranged in such a manner thatplate surfaces are directed in the machine body width direction, andprovided ranging from the front part of the machine body 2 to a rearpart.

As shown in FIG. 5, the track frame 14 is attached to a lower part of anouter side surface of the main frame 13 via attachment members 17. Themotor attachment portion 15 is provided in a rear upper part of theouter side surface of the main frame 13.

The support frame 16 is attached to a rear part of the main frame 13.

As shown in FIGS. 6 and 7, the support frame 16 has an inner wall (firstwall) 18, an outer wall (second wall) 19, a front wall (fourth wall) 20,a rear wall (third wall) 21, a partition wall (fifth wall) 22, a bottomplate 23, a reinforcing wall 24, and a cylinder attachment portion 25.

The inner wall 18 and the outer wall 19 are provided so as to face eachother and spaced from each other in the machine body width direction.The outer wall 19 is positioned on the machine body outer side of theinner wall 18.

The inner wall 18 is formed by for example one plate material. In a rearpart of this inner wall 18, a cut-away portion 26 is formed into apenetrating shape in the machine body width direction. This cut-awayportion 26 has a front edge portion 27, an upper edge portion 28, and alower edge portion 29, and is formed into an open shape toward the rearside. As shown in FIG. 8, a locking member 32 is provided on a surfaceof the inner wall 18 on the machine body inner side. This locking member32 is formed by a rod material, and provided in the vicinity of thefront edge portion 27 of the cut-away portion 26 and in an up-downintermediate part of the front edge portion 27.

As shown in FIG. 6, the outer wall 19 has a main part 30 and a sub part31 formed by plate materials. The sub part 31 is fixed to a front end ofthe main part 30 in a forward projecting form. In an up-downintermediate part of a rear part of the main part 30, a placement hole33 formed by an annular edge portion is formed. It should be noted thatthe main part 30 and the sub part 31 may be formed by for example oneplate material and integrated with each other.

As shown in FIGS. 1, 6, and 7, the front wall 20 has a first part 34, asecond part 35, and a third part 36. The first part 34 is secured to arear end 38 of the main frame 13. This first part 34 is formed into afront-upward inclined shape along the rear end 38 of the main frame 13.The second part 35 is extended from an upper end of the first part 34toward the front obliquely upper side. This second part 35 is secured toa corner portion 40 between the rear end 38 and an upper end 39 of themain frame 13. The third part 36 is extended from a front end of thesecond part 35 in a front-downward inclined shape. This third part 36 issecured to a rear part of the upper end 39 of the main frame 13. A linkattachment portion 41 is fixed to an upper surface of the third part 36.

As shown in FIGS. 6 and 8, since the front wall 20 is provided in anintermediate part of the main frame 13 in the machine body widthdirection, the front wall projects not only toward the machine bodyinner side of the main frame 13 but also toward the machine body outerside. A part of the front wall 20 projecting from the main frame 13toward the machine body outer side serves as a fender covering a rearpart of the traveling device 5. An edge portion 18A formed in a frontpart of the inner wall 18 is formed into a shape along a back surface ofthe first part 34 and upper surfaces of the second part 35 and the thirdpart 36 of the front wall 20. The first part 34, the second part 35, andthe third part 36 are secured to the edge portion 18A of the inner wall18. The outer wall 19 is secured to machine body outer side end parts ofthe first part 34, the second part 35, and the third part 36. Therefore,the front wall 20 couples the front part of the inner wall 18 and afront part of the outer wall 19. It should be noted that it issufficient if parts of the first part 34, the second part 35, and thethird part 36 are secured to the outer wall 19.

As shown in FIGS. 6 and 8, the rear wall 21 is extended from a rear endof the outer wall 19 (rear end of the main part 30) toward the machinebody inner side. A machine body inner side end part of this rear wall 21is fixed to a rear end part of the inner wall 18. Therefore, the rearwall 21 couples the rear part of the inner wall 18 and a rear part ofthe outer wall 19. A stay 37 is provided in the rear wall 21. This stay37 is provided on the machine body inner side of a back surface of therear wall 21 at a position corresponding to the rear side of the lockingmember 32.

It should be noted that the rear wall 21 and the outer wall 19 areintegrated with each other by one plate material in the firstembodiment.

As shown in FIGS. 1 and 6, the partition wall 22 is provided between thefront wall 20 and the rear wall 21 and between the inner wall 18 and theouter wall 19. The partition wall 22 is positioned in the vicinity ofthe front edge portion 27 of the cut-away portion 26 and couples theinner wall 18 and the outer wall 19.

As shown in FIGS. 2, 3, and 4, the bottom plate 23 is provided betweenthe inner wall 18 and the outer wall 19 along the lower edge portion 29of the cut-away portion 26. This bottom plate 23 couples a lower end ofthe partition wall 22 and a lower end of the rear wall 21. The bottomplate 23 couples the inner wall 18 and the outer wall 19. The bottomplate 23 has an opening portion 42 formed by an annular edge portion,and a lid plate 43 closing this opening portion 42. The opening portion42 is formed in a front-rear intermediate part of the bottom plate 23and in an intermediate part in the machine body width direction. The lidplate 43 is detachably attached to a lower surface of the bottom plate23 by bolts 44. A part on the lower side of the bottom plate 23 is notclosed but formed into an open shape.

As shown in FIGS. 1 and 6, the reinforcing wall 24 is provided betweenthe inner wall 18 and the outer wall 19 ranging from an upper part ofthe second part 35 of the front wall 20 to an upper part of the rearwall 21, and couples the inner wall 18 and the outer wall 19. Thisreinforcing wall 24 has a front part 45, an intermediate part 46, and arear part 47. The front part 45 is provided ranging from the upper partof the second part 35 of the front wall 20 to an upper end of thepartition wall 22. The intermediate part 46 is extended from a rear endof the front part 45 toward the rear obliquely upper side. The rear part47 is extended from an upper end of the intermediate part 46 toward therear side, and connected to a front surface of the rear wall 21. Athrough hole 48 formed by an annular edge portion is formed in the frontpart 45. A support plate 49 is provided in a corner part between thefront part 45 and the intermediate part 46 in a machine body outer sideend part.

As shown in FIGS. 1, 3, 6, and 7, the cylinder attachment portion 25 isprovided between lower parts of the inner wall 18 and the outer wall 19.This cylinder attachment portion 25 has a right plate member 50R and aleft plate member 50L. The right plate member 50R and the left platemember 50L face each other in the machine body width direction. Frontends of the plate members 50R, 50L are secured to a back surface lowerpart of the first part 34 of the front wall 20. Front portions 50 a ofthe plate members 50R, 50L extend rearward from the back surface lowerend side of the first part 34. Cylinder support portions 52 are providedin the front portions 50 a of the plate members 50R, 50L. Rear portions50 b of the plate members 50R, 50L are bent toward the upper side, andupper ends are secured to a front part lower surface of the bottom plate23.

As shown in FIG. 11, crawler type traveling devices 5 are adopted as thetraveling devices 5 in the first embodiment. The traveling devices 5 areprovided on the left side and the right side of the machine body 2.

Each of the traveling devices 5 has a drive wheel 53, front and reardriven wheels 54, a traveling motor 55, a crawler belt 56, and aplurality of track rollers 57. The front and rear driven wheels 54 andthe track rollers 57 are supported on the track frame 14 rotatably aboutthe lateral axis (axis in the machine body width direction). Thetraveling motor 55 is attached to the motor attachment portion 15. Thedrive wheel 53 is attached to the traveling motor 55, and driven by thistraveling motor 55 and rotated about the lateral axis. The crawler belt56 is formed by an endless belt and looped over the front and reardriven wheels 54, the track rollers 57, and the drive wheel 53. Byrotating the drive wheel 53, the crawler belt 56 cyclically runs in thecircumferential direction, and the working machine 1 goes forward orrearward. It should be noted that as shown in FIG. 14, the travelingdevices 5 may be wheel type traveling devices 5.

As shown in FIG. 11, each of the working devices 4 has a boom 58, aworking tool 59, a lift link 60, a control link 61, a boom cylinder 62,and a working tool cylinder (bucket cylinder) 63. The boom 58 isprovided on the side of the machine body 2 and on the side of the cabin3 oscillatably in the up and down direction (up-down direction). Thebooms 58 are respectively provided on the right side and the left sideof the cabin 3. The inner wall 18 is provided on the side of each of thebooms 58 which is the machine body inner side. The outer wall 19 isprovided on the side of the boom 58 which is the side opposite to theinner wall 18 (machine body outer side).

A bucket is provided as the working tool 59 in the first embodiment.This bucket 59 is placed in the boom 58. In detail, the bucket 59 isprovided in a leading end part (front end part) of the boom 58oscillatably in the up and down direction. The lift link 60 and thecontrol link 61 support a base part (rear part) of the boom 58 in such amanner that the boom 58 is oscillatable in the up and down direction. Bybeing extended and contracted, the boom cylinder 62 lifts and lowers theboom 58. By being extended and contracted, the working tool cylinder 63oscillates the bucket 59.

Each of the left and right booms 58 is provided at a positioncorresponding to a part between the inner wall 18 and the outer wall 19of the support frame 16. Front parts of the left and right booms 58 arecoupled to each other by a coupling member 64, and the base parts of thebooms 58 are coupled to each other by a coupling member 64.

The lift links 60, the control links 61, and the boom cylinders 62 arerespectively provided on the left side and the right side of the machinebody 2 in correspondence with the left and right booms 58.

As shown in FIG. 1, the lift link 60 is vertically provided in a rearpart of the base part of the boom 58. An upper part (one end side) ofthis lift link 60 is supported on a rear base part of the boom 58pivotably rotatably about the lateral axis by a pivot shaft (first pivotshaft) 66. A lower part (other end side) of the lift link 60 is insertedbetween the inner wall 18 and the outer wall 19. The lower part of thislift link 60 is supported between the inner wall 18 and the supportplate 49 pivotably rotatably about the lateral axis by a pivot shaft(second pivot shaft) 67.

Therefore, the inner wall 18 is provided on the side of the lift link 60which is the machine body inner side. The outer wall 19 is provided onthe side of the lift link 60 which is the side opposite to the innerwall 18 (machine body outer side).

A cylinder tube 68 of the boom cylinder 62 is provided between the innerwall 18 and the outer wall 19. Therefore, the inner wall 18 is providedon the side of the boom cylinder 62 which is the machine body innerside. The outer wall 19 is provided on the side of the boom cylinder 62which is the side opposite to the inner wall 18 (machine body outerside).

This cylinder tube 68 is positioned on the front side of the lift link60, and inserted through the through hole 48 (refer to FIG. 6). An upperpart (piston rod) of the boom cylinder 62 is supported on the base partof the boom 58 pivotably rotatably about the lateral axis by a pivotshaft (third pivot shaft) 69. The third pivot shaft 69 is positioned onthe front side of the first pivot shaft 66.

A lower part (on the bottom side of the cylinder tube 68) of the boomcylinder 62 is supported between the cylinder support portions 52 of thecylinder attachment portion 25 pivotably rotatably about the lateralaxis by a pivot shaft (fourth pivot shaft) 70. The fourth pivot shaft 70is positioned on the lower side of the second pivot shaft 67.

The control link 61 is provided on the front side of the lift link 60and on the side of a lower part of the base part of the boom 58. One endof the control link 61 is supported on the link attachment portion 41pivotably rotatably about the lateral axis by a pivot shaft (fifth pivotshaft) 71. The other end of the control link 61 is supported on thelower part of the base part of the boom 58 pivotably rotatably about thelateral axis by a pivot shaft (sixth pivot shaft) 72. The fifth pivotshaft 71 is positioned on the front side of the third pivot shaft 69.The sixth pivot shaft 72 is positioned between the first pivot shaft 66and the third pivot shaft 69. The sixth pivot shaft 72 is positioned onthe front side and the upper side of the second pivot shaft 67.

As shown in FIGS. 9 and 10, an engine (diesel engine) 73, a radiator 74,and a battery 75 are mounted in the rear part in the machine body 2. Theradiator 74 is provided on the rear side of the engine 73. A cooling fan76 is provided between the engine 73 and the radiator 74. This coolingfan 76 is driven by an output shaft of the engine 73 and blows airtoward the rear side (radiator 74). The battery 75 is provided on theright side of the cooling fan 76. A part on the rear side of theradiator 74 is covered by a bonnet cover 77. This bonnet cover 77 isattached to rear ends of the support frames 16. The cooling windgenerated by the cooling fan 77 is discharged to the rear side of themachine body 2 through an air ventilation part formed in the bonnetcover 77.

In a part on the front side of the engine 73, a plurality of hydraulicpumps 78, 79, 80, 81 is provided in line in the front and reardirection. In the first embodiment, the hydraulic pump 78 is a travelingpump, the hydraulic pump 79 is a main pump, the hydraulic pump 80 is asub pump, and the hydraulic pump 81 is a pilot pump. These hydraulicpumps 78, 79, 80, 81 supply working oil in a working oil tank 84 topredetermined hydraulic devices via control valves.

The traveling pump 78 is a hydraulic pump that drives the travelingmotors (hydraulic motors) 55. In addition, this traveling pump 78 is avariable capacity hydraulic pump forming part of a hydrostaticcontinuously variable transmission together with the traveling motors55. The main pump 79, the sub pump 80, and the pilot pump 81 areconstant capacity gear pumps. The main pump 79 is a hydraulic pump thatdrives hydraulic actuators installed in the working devices 4 andhydraulic actuators installed in hydraulic attachment which are attachedto the working devices 4. The sub pump 80 is a hydraulic pump used forincreasing an amount of the working oil. The pilot pump 81 is mainlyused for supplying control signal pressure.

A particle removal device 82 is provided on the front side of an upperpart of the engine 73. This particle removal device 82 is formed by aDPF (Diesel Particulate Filter) in the first embodiment. This DPF 82 isconnected to an exhaust manifold of the engine 73, and removes minuteparticles containing harmful substances in an exhaust gas of the engine73.

A fuel tank 83 and the working oil tank 84 are mounted in the front partin the machine body 2. The working oil tank 84 is a tank that stores theworking oil for activating the hydraulic actuators, the tank beingprovided on the right side in the machine body 2.

The fuel tank 83 is a tank that stores fuel of the engine 73, the tankbeing provided on the left side in the machine body 2. This fuel tank 83extends forward from the left side of a front part of the engine 73.This fuel tank 83 has a fuel tank main body (referred to as the firsttank main body) 86, a feeding pipe (referred to as the first feedingpipe) 87, and a cap (referred to as the first cap) 88. The fuel isstored in the first tank main body 86. The first feeding pipe 87 has afirst pipe portion 89 extending upward from a front-rear intermediatepart on an upper surface of the first tank main body 86, and a secondpipe portion 90 extending from this first pipe portion 89 toward themachine body outer side (left side). The second pipe portion 90 ispositioned on the upper side of the main frame 13. A left end part ofthe second pipe portion 90 serves as a feeding port (referred to as thefirst feeding port) 91 opened toward the left side. The fuel is fed fromthis first feeding port 91. Therefore, the fuel can be fed to the fueltank 83 from the left side of the machine body 2 which is the outer sideof the machine body 2. The first feeding port 91 is openably closed bythe first cap 88.

The working machine 1 has a urea SCR (Selective Catalytic Reduction)system. This urea SCR system is a system to, by injecting a urea aqueoussolution into a distribution route through which the exhaust gas of theengine is distributed, hydrolyze the urea aqueous solution under a hightemperature, generate an ammonia gas, and reduce nitrogen oxide to anitrogen gas and water vapor by this ammonia gas. Accordingly, the ureaSCR system can eliminate nitrogen oxide in an exhaust gas dischargedfrom an engine.

The urea aqueous solution in a liquid state is stored in a urea aqueoussolution tank and mounted in the working machine. The melting point ofthis urea aqueous solution is −11° C. Thus, there is a fear that theurea aqueous solution is frozen by a decrease in an ambient temperature.When a temperature of the urea aqueous solution is increased to be apredetermined temperature (such as 50° C.) or higher, part of the ureaaqueous solution is gasified and evaporated, and concentration of theurea aqueous solution is changed. Therefore, the urea aqueous solutiontank has to be arranged in a place where a temperature environment isfavorable.

As shown in FIGS. 9 and 10, this urea SCR system has a SCR catalyst(selective catalytic reduction catalyst) 92, a catalyst case 93accommodating this SCR catalyst 92, a urea aqueous solution tank 94, anda SCR pump 95.

The catalyst case 93 is provided on the rear side of the DPF 82 and onthe upper side of the front part of the engine 73. This catalyst case 93is connected to the DPF 82 via a connection pipe 96.

The urea aqueous solution tank 94 is a tank that stores a urea aqueoussolution. The SCR pump 95 is connected to the urea aqueous solution tank94 and the connection pipe 96 by hoses (not shown). This SCR pump 95pumps up the urea aqueous solution in the urea aqueous solution tank 94and injects the urea aqueous solution into the connection pipe 96 via aninjection nozzle. The urea aqueous solution injected into the connectionpipe 96 is hydrolyzed under a high temperature by the exhaust gas of theengine 73 passing through the DPF 82. Thereby, an ammonia gas isgenerated, and by this ammonia gas, nitrogen oxide in the exhaust gas ofthe engine 73 is reduced to a nitrogen gas and water vapor. Thisreduction reaction is facilitated by the SCR catalyst 92 in the catalystcase 93. The purified exhaust gas of the engine 73 is discharged to theatmosphere from the catalyst case 93.

As shown in FIG. 1, the urea aqueous solution tank 94 is provided on therear side of the lift link 60 and the boom cylinder 62 and on the lowerside of the boom 58. The urea aqueous solution tank 94 is disposed onthe bottom plate 23.

As shown in FIGS. 1 and 2, the urea aqueous solution tank 94 is providedbetween the front wall 20 and the rear wall 21. The urea aqueoussolution tank 94 is also provided between the inner wall 18 and theouter wall 19 (by utilizing a space between the inner wall 18 and theouter wall 19). The urea aqueous solution tank 94 is provided betweenthe partition wall 22 positioned on the rear side of the front wall 20,and the rear wall 21. In detail, the partition wall 22 is positioned onthe front side of the urea aqueous solution tank 94, the rear wall 21 ispositioned on the rear side of the urea aqueous solution tank 94, theouter wall 19 is positioned on the side of the urea aqueous solutiontank 94 which is the side opposite to the inner wall 18, and theintermediate part 46 and the rear part 47 of the reinforcing wall 24 arepositioned on the upper side of the urea aqueous solution tank 94.Therefore, an installment portion 97 in which the urea aqueous solutiontank 94 is installed is formed by the bottom plate 23, the partitionwall 22, the rear wall 21, the outer wall 19, and the intermediate part46 and the rear part 47 of the reinforcing wall 24. It should be notedthat it is sufficient if the urea aqueous solution tank 94 is providedbetween the front wall 20 and the rear wall 21. The urea aqueoussolution tank 94 may be provided on the rear side of the cylinder tube68 between the first part 34 of the front wall 20 and the rear wall 21,or may be provided in other places.

As shown in FIGS. 9 and 10, the urea aqueous solution tank 94 isprovided on the side (left side) and the rear side of the engine 73. Theurea aqueous solution tank 94 is provided on the rear side of the engine73 and on the side (left side) of the radiator 74. As shown in FIGS. 1and 11, the urea aqueous solution tank 94 is provided on the rear sideof the traveling device 5. In other words, the installment portion 97 ispositioned on the left side and the rear side of the engine 73. Theinstallment portion 97 is positioned on the rear side of the engine 73and on the left side of the radiator 74. Further, the installmentportion 97 is provided on the rear side of the traveling device 5.

Further in detail, the urea aqueous solution tank 94 is provided in sucha manner that a front surface 94A of the urea aqueous solution tank 94is positioned on the rear side of a back surface 73A of the engine 73.The urea aqueous solution tank 94 is provided in such a manner that aside surface 94B of the urea aqueous solution tank 94 and a side surface74A of the radiator 74 are overlapped with each other in the machinebody width direction. The urea aqueous solution tank 94 is provided insuch a manner that the side surface 94B of the urea aqueous solutiontank 94 and a side surface 76A of the cooling fan 76 are overlapped witheach other in the machine body width direction. The urea aqueoussolution tank 94 is provided in such a manner that the front surface 94Aof the urea aqueous solution tank 94 and the crawler belt 56 areoverlapped with each other in the front and rear direction on the rearside of the traveling device 5.

It should be noted that in the first embodiment, the urea aqueoussolution tank 94 (installment portion 97) meets all a first condition tobe positioned on the side and the rear side of the engine 73, a secondcondition to be secondly positioned on the side of the radiator 74, anda third condition to be positioned on the rear side of the travelingdevice 5. However, the urea aqueous solution tank 94 may be installed soas to meet any of the first to third conditions. The urea aqueoussolution tank 94 has a urea aqueous solution tank main body (referred toas the second tank main body) 98, a feeding pipe (referred to as thesecond feeding pipe) 99, a cap (referred to as the second cap) 100, asupply portion 101, and a discharge portion 102.

The urea aqueous solution is stored in the second tank main body 98. Amachine body inner part of this second tank main body 98 is extendedover from the installment portion 97 to the side where the engine 73 isarranged via the cut-away portion 26. As shown in FIG. 3, on the uppersurface side of the second tank main body 98 and on the machine bodyouter side (left side), an insertion port 103 formed by an annular edgeportion is formed. The second tank main body 98 is formed into anupright form in which up-down width is greater than front-rear width.

As shown in FIG. 4, the second tank main body 98 is fixed by anattachment plate 104. This attachment plate 104 is provided in anup-down intermediate part of the second tank main body 98 on the machinebody inner side of the second tank main body 98. A front end part of theattachment plate 104 serves as a catching portion 105, and a rear endpart of the attachment plate 104 serves as an attachment portion 114.The catching portion 105 is caught onto the locking member 32 providedin the inner wall 18. The attachment portion 114 is fixed to the stay 37provided in the rear wall 21 by a bolt 106. By this attachment plate104, the second tank main body 98 is pushed onto the outer wall 19.Thereby, the second tank main body 98 is fixed. It should be noted thata cushion member 107 is provided between the second tank main body 98and the outer wall 19, and a cushion member 107 is provided between thesecond tank main body 98 and the attachment plate 104.

A gap 108 is provided between the second tank main body 98 and thepartition wall 22, and a gap 108 is provided between the second tankmain body 98 and the rear wall 21.

As shown in FIG. 3, the second feeding pipe 99 is a pipe for feeding theurea aqueous solution into the second tank main body 98. This secondfeeding pipe 99 is inserted into the second tank main body 98 from theinsertion port 103. The second feeding pipe 99 is attached to anattachment member 109 formed by a plate material. The attachment member109 has a recessed portion 110 recessed inward from the machine bodyouter side, and a flange portion 111 extended from an end part of thisrecessed portion 110. The recessed portion 110 is inserted into theinstallment portion 97 from the placement hole 33. An upper part of thesecond feeding pipe 99 is fixed to a bottom wall 112 of this recessedportion 110. The flange portion 111 is overlapped with a circumferenceof the placement hole 33 on an outer surface of the outer wall 19 andfixed by a screw or the like.

A feeding port (referred to as the second feeding port) 113 is formed inan upper end of the second feeding pipe 99. The urea aqueous solution isfed from this second feeding port 113. The urea aqueous solution can befed to the urea aqueous solution tank 94 from the left side of themachine body 2 which is the outer side of the machine body 2. Therefore,the first feeding port 91 serving as the feeding port of the fuel tank83 and the second feeding port 113 serving as the feeding port of theurea aqueous solution tank 94 are arranged in a side part of the machinebody 2 on the same side.

The second feeding port 113 is openably closed by the second cap 100.The second feeding port 113 and the second cap 100 are positioned in therecessed portion 110.

As shown in FIG. 2, the supply portion 101 is a portion from which theurea aqueous solution is discharged in order to supply the urea aqueoussolution into the exhaust gas of the engine 73, and is connected to theSCR pump 95 by the hose.

The discharge portion 102 is a portion from which the urea aqueoussolution is discharged in order to remove the urea aqueous solution inthe urea aqueous solution tank 94, and is provided at a positioncorresponding to the opening portion 42 of the bottom plate 23.Therefore, by detaching the lid plate 43, the urea aqueous solution inthe urea aqueous solution tank 94 can be discharged to the lower side ofthe machine body 2 from the discharge portion 102.

There is a fear that the urea aqueous solution is frozen by a decreasein an ambient temperature. When a temperature of the urea aqueoussolution is increased to be a predetermined temperature or higher, partof the urea aqueous solution is gasified and evaporated, andconcentration of the urea aqueous solution is changed. Therefore, theurea aqueous solution tank 94 is desirably arranged in a place where atemperature environment is favorable. In the first embodiment, a placesurrounded by the bottom plate 23, the partition wall 22, the rear wall21, the outer wall 19, and the intermediate part 46 and the rear part 47of the reinforcing wall 24 serves as the installment portion in whichthe urea aqueous solution tank 94 is installed. Thereby, the ureaaqueous solution tank 94 is installed in the place where the temperatureenvironment is favorable, so that the urea aqueous solution tank 94 canbe favorably mounted in the working machine 1 such as a compact trackloader having the booms 58 provided on the sides of the machine body 2and the cabin 3 and the lift links 60 pivotably supported on the rearparts of the booms 58.

The urea aqueous solution tank 94 is arranged on the side of the coolingfan 76, and arranged in a place where the urea aqueous solution tank 94is not exposed to the cooling wind passing through the radiator 74. Inother words, the urea aqueous solution tank 94 is arranged on the sidewhere the cooling fan 76 suctions air. Thereby, it can also be said thatthe temperature environment in the place where the urea aqueous solutiontank 94 is arranged is favorable.

Since the urea aqueous solution tank 94 is formed into an upright form(vertically elongated), a remaining amount sensor that detects aremaining amount of the urea aqueous solution works properly. That is,with a horizontally elongated urea aqueous solution tank, when theworking machine 1 is inclined, the urea aqueous solution is greatlyslanted and the remaining amount sensor does not properly work.Meanwhile, with the upright urea aqueous solution tank 94, when theworking machine 1 is inclined, the urea aqueous solution is not greatlyslanted. Thus, the remaining amount sensor works properly.

Also in a case where a liquid level of the urea aqueous solution is seenin order to confirm the remaining amount of the urea aqueous solution,with the upright urea aqueous solution tank 94, inclination of theliquid level of the urea aqueous solution when the working machine 1 isinclined is more moderate. Thus, the amount of the urea aqueous solutionis more easily found than with the horizontally elongated urea aqueoussolution tank.

Since the installment portion 97 in which the urea aqueous solution tank94 is installed is formed in a rear part of the support frame 16, heightof the installment portion 97 can be sufficiently ensured and theupright urea aqueous solution tank 94 can be arranged.

Upon providing the urea aqueous solution tank 94 in the support frame16, by providing the urea aqueous solution tank 94 on the rear side ofthe lift link 60, arrangement and structures of the members forming theworking device 4 are not influenced.

Since the installment portion 97 is formed in the rear part of thesupport frame 16, installment of the urea aqueous solution tank 94 doesnot influence arrangement of other devices, members, and the like in themachine body 2.

The urea aqueous solution tank 94 is arranged on the inner side of theouter wall 19 of the support frame 16 forming the side part of themachine body 2, and the urea aqueous solution can be fed to the ureaaqueous solution tank 94 from the outer side of the outer wall 19.Thereby, accessibility to the feeding port of the urea aqueous solutiontank 94 is favorable, and the urea aqueous solution can be easily fed.The opening portion 42 is provided in the bottom plate 23 on which theurea aqueous solution tank 94 is disposed, and the discharge portion 102is provided at the position corresponding to this opening portion 42.Thereby, accessibility to the discharge portion 102 of the urea aqueoussolution tank 94 is favorable, and the urea aqueous solution in the ureaaqueous solution tank 94 is easily drained.

By arranging the first feeding port 91 serving as the feeding port ofthe fuel and the second feeding port 113 serving as the feeding port ofthe urea aqueous solution in the side part of the machine body 2 on thesame side, workability at the time of feeding the fuel and the ureaaqueous solution is favorable.

By providing the gap 108 between the second tank main body 98 and thepartition wall 22 and providing the gap 108 between the second tank mainbody 98 and the rear wall 21, when part of the urea aqueous solution isgasified and the second tank main body 98 is expanded, this expansioncan be released to the front side and the rear side.

By providing the urea aqueous solution tank 94 on the side and the rearside of the engine 73, or by providing the urea aqueous solution tank 94on the side of the radiator 74, or by providing the urea aqueoussolution tank 94 on the rear side of the engine 73 and on the side ofthe radiator 74, the urea aqueous solution tank 94 can be arranged in aplace not easily influenced by the temperature and the wind in themachine body 2. In particular, by bringing a part between the front wall20 and the rear wall 21 in the support frame 16 into an environmentallyexcellent place not easily influenced by the temperature and the wind,and installing the urea aqueous solution tank 94 in the above place,freezing, evaporation, and the like of the urea aqueous solution can besuppressed. In addition, the urea aqueous solution tank 94 can bearranged in a place where height can be sufficiently ensured.

Second Embodiment

FIGS. 15 to 20 show a second embodiment of the present invention.Elements having substantially the same function as those in the firstembodiment will be numbered the same here, and will not be describedand/or illustrated again in detail here for the sake of brevity. Thedriver's seat 6 is attached to a bottom portion 126 of the cabin 3. Adriver's exit 134 for a driver getting on and off is provided on a frontsurface of the cabin 3. This driver's exit 134 can be opened and closedby a transparent front panel 135. This front panel 135 can be opened andclosed from the outer side of the cabin 3 (cabin exterior side) and theinner side (cabin interior side).

Pivotably supporting brackets 131 that pivotably supports the cabin 3are provided in a front part of the upper frame portion 12. As shown inFIG. 15, coupling brackets 132 are provided in a back surface lower partof the cabin 3. The coupling brackets 132 (rear part of the cabin 3) aresupported on the pivotably supporting brackets 131 pivotably rotatablyabout the lateral axis via a support shaft 133 in the machine body widthdirection. Therefore, by rotating the cabin 3 about the support shaft133, the cabin 3 can be oscillated upward from a state where the cabin 3is disposed on the machine body 2 shown in FIG. 15.

A vertical plate 116 and a step 114 are provided in the front partinside the machine body 2 on the front side of the driver's seat 6. Thevertical plate 116 is vertically arranged in such a manner that platesurfaces face the front side and the rear side, and spaced from thefront frame portion 10 on the rear side. The step 114 is a place onwhich the driver seated on the driver's seat 6 sets his/her feet. Thestep 114 is arranged between the front frame portion 10 and the verticalplate 116. The step 114 is provided at a height position of an up-downintermediate part of the front part of the machine body 2. The step 114is provided ranging from the front frame portion 10 to the verticalplate 116, and also ranging from the right side frame portion 8 to theleft side frame portion 9.

The step 114 and the vertical plate 116 are attached to the machine body2. A rear end part of the step 114 is attached to the vertical plate116. The bottom portion 126 of the cabin 3 is provided on the rear sideof the step 114. Therefore, a lower surface part of the cabin 3corresponding to the upper side of the step 114 is formed into an openedform.

As shown in FIG. 18, crawler type traveling devices 5 are adopted as thetraveling devices 5 in the second embodiment, too. The traveling devices5 are provided on the left side and the right side of the machine body2. It should be noted that as shown in FIG. 29, the traveling devices 5may be wheel type traveling devices 5. A fuel tank 83 and a urea aqueoussolution tank 94 are mounted in the front part in the machine body 2.

The fuel tank 83 and the urea aqueous solution tank 94 are provided onone side in the machine body width direction in the machine body 2. Inthe second embodiment, the tanks are provided on the left side in themachine body 2. The first feeding pipe 87 has a connection pipe(referred to as the first connection. pipe) 117, and an extension pipe(referred to as the first extension pipe) 118. The first connection pipe117 is provided in an upper and left part of a back surface of the firsttank main body 86. One end of this first connection pipe 117 isconnected to the first tank main body 86. The other end of the firstconnection pipe 117 is bent upward. A lower portion 119 of the firstextension pipe 118 is connected to the first connection pipe 117 andextends upward from the first connection pipe 117. An upper portion 120of the first extension pipe 118 extends toward the machine body outerside (left side) from an upper end of the lower portion 119 of the firstextension pipe 118, and is positioned on the upper side of the mainframe 13. A left end part of the upper portion 120 of this firstextension pipe 118 serves as a feeding port (referred to as the firstfeeding port) 91 opened toward the left side.

The second feeding pipe 99 has a connection pipe (referred to as thesecond connection pipe) 121, and an extension pipe (referred to as thesecond extension pipe) 122. The second connection pipe 121 is providedin a front upper part of the second tank main body 98 on the left sideof the second tank main body 98. One end of this second connection pipe121 is connected to the second tank main body 98. The other end of thesecond connection pipe 121 is directed to the front obliquely upperside. A lower portion 123 of the second extension pipe 122 is connectedto the second connection pipe 121 and extends upward from the secondconnection pipe 121. An upper portion 124 of the second extension pipe122 extends toward the machine body outer side (left side) from an upperend of the lower portion 123 of the second extension pipe 122, and ispositioned on the upper side of the main frame 13. A left end part ofthe upper portion 124 of this second extension pipe 122 serves as afeeding port (referred to as the second feeding port) 113 opened towardthe left side.

The fuel tank 83 (first tank main body 86) is arranged on the rear sideof the vertical plate 116 and in the vicinity of the vertical plate 116.The second tank main body 98 is arranged on the rear side of the firsttank main body 86 and in the vicinity of the first tank main body 86.That is, a rear surface of the first tank main body 86 and a frontsurface of the second tank main body 98 face each other in the vicinity.The rear surface of the first tank main body 86 and the front surface ofthe second tank main body 98 are overlapped with each other in the frontand rear direction.

The first extension pipe 118 is positioned on the rear side and in thevicinity of the second extension pipe 122. Therefore, the feeding port(first feeding port) 91 formed in the first feeding pipe 87 and thefeeding port (second feeding port) 113 formed in the second feeding pipe99 are directed to the same side (left side) and provided in line in thefront and rear direction. The fuel and the urea aqueous solution can befed from the same side of the machine body. Thereby, it is useful whenthe fuel and the urea aqueous solution are fed.

The urea aqueous solution tank 94 (second tank main body 98) and thefuel tank 83 (first tank main body 86) are provided on the front side ofthe engine 73. In the second embodiment, the second tank main body 98 isprovided on the front side of the engine 73 and on the side (left side)of the hydraulic pumps 78, 79. The fuel tank 83 (first tank main body86) is also provided on the front side of the engine 73 and on the side(left side) of the hydraulic pumps 80, 81.

That is, on the front side and the left side of the engine 73, the firsttank main body 86 and the second tank main body 98 are provided. Thesecond tank main body 98 is arranged between the first tank main body 86and the engine 73.

Third Embodiment

FIGS. 21 and 22 show a third embodiment of the present invention.Elements having substantially the same function as those in the secondembodiment will be numbered the same here, and will not be describedand/or illustrated again in detail here for the sake of brevity.

In the third embodiment, a urea aqueous solution tank 94 is arranged onthe rear side of a vertical plate 116 and in the vicinity of thevertical plate 116. A first tank main body 86 (fuel tank 83) is arrangedon the rear side of a second tank main body 98 and in the vicinity ofthe second tank main body 98. That is, a front surface of the first tankmain body 86 and a rear surface of the second tank main body 98 faceeach other in the vicinity. The front surface of the first tank mainbody 86 and the rear surface of the second tank main body 98 areoverlapped with each other in the front and rear direction.

The first tank main body 86 is provided on the front side of the engine73 and on the side (left side) of the hydraulic pumps 79, 80, 81. Thesecond tank main body 98 is provided on the front side of the engine 73and on the front side of the hydraulic pump 81.

That is, on the front side and the left side of the engine 73, the firsttank main body 86 and the second tank main body 98 are provided. Thefirst tank main body 86 is arranged between the second tank main body 98and the engine 73.

Also in the third embodiment, as well as the second embodiment, a firstextension pipe 118 is positioned on the rear side and in the vicinity ofa second extension pipe 122. A feeding port (first feeding port) 91formed in a first feeding pipe 87 and a feeding port (second feedingport) 113 formed in a second feeding pipe 99 are directed to the sameside (left side) and provided in line in the front and rear direction.The other configurations are the same as those of the second embodiment.

Fourth Embodiment

FIGS. 23 and 24 show a fourth embodiment. Elements having substantiallythe same function as those in the second and third embodiments will benumbered the same here, and will not be described and/or illustratedagain in detail here for the sake of brevity.

In the fourth embodiment, a second feeding pipe 99 does not have thesecond extension pipe 122 described in the second embodiment. Therefore,this second feeding pipe 99 is formed by a single pipe member. A secondfeeding port 113 of this second feeding pipe 99 and a cap 125 closingthis second feeding port 113 are positioned on the lower side of abottom portion 126 of a cabin 3. In this fourth embodiment, the secondfeeding port 113 can be exposed to an exterior in a state where thecabin 3 is oscillated upward as shown by an imaginary line in FIG. 23.Therefore, in a case where a urea aqueous solution is fed to a ureaaqueous solution tank 94, feeding is done in a state where the cabin 3is oscillated upward. In addition, fuel is fed to a fuel tank 83 fromthe left side of a machine body 2 which is the outer side of the machinebody 2. Thereby, a confusion of feeding of the urea aqueous solutionwith feeding of the fuel can be prevented. The other configurations arethe same as those of the second embodiment.

Fifth Embodiment

FIGS. 25 and 26 show a fifth embodiment. Elements having substantiallythe same function as those in the second to fourth embodiments will benumbered the same here, and will not be described and/or illustratedagain in detail here for the sake of brevity.

In the fifth embodiment, a clearance is provided between a side end(left end) of a step 114 and a side frame portion 9 (left side frameportion 9). On the side where this clearance is provided which is theside (left side) of the step 114, a urea aqueous solution tank 94(second tank main body 98) is provided. Therefore, the urea aqueoussolution tank 94 (second tank main body 98) is provided in a machinebody 2 and in a cabin 3. In a front part of the machine body 2, asupport member 127 supporting the urea aqueous solution tank 94 isprovided ranging from a front frame portion 10 to a vertical plate 116.The support member 127 is attached to the machine body 2. In detail,this support member 127 has a lower wall 127 a, a front vertical wall127 b, a rear vertical wall 127 c, a side vertical wall 127 d, and anextension wall 127 e. The lower wall 127 a is spaced from a bottom frameportion 11 of the machine body 2 on the upper side. The front verticalwall 127 b extends upward from a front end of the lower wall 127 a. Therear vertical wall 127 c extends upward from a rear end of the lowerwall 127 a. The side vertical wall 127 d extends forward from a machinebody inner side end part of the rear vertical wall 127 c. A front endpart of this side vertical wall 127 d extends up to the front frameportion 10. The extension wall 127 e extends forward from an upper endof the front vertical wall 127 b. A front end part of this extensionwall 127 e extends up to the front frame portion 10. Upper ends of thefront vertical wall 127 b, the rear vertical wall 127 c, and the sidevertical wall 127 d are positioned at a height position of a treadsurface 114 a of the step 114. A part surrounded by the lower wall 127a, the front vertical wall 127 b, the rear vertical wall 127 c, the sidevertical wall 127 d, and the left side frame portion 9 serves as ahousing portion 127 g housing the urea aqueous solution tank 94. Theurea aqueous solution tank 94 is disposed on the lower wall 127 a of thesupport member 127 and attached to the support member 127.

A second feeding pipe 99 does not have the second extension pipe 122described in the second embodiment. Therefore, this second feeding pipe99 is formed by a single pipe member.

The second feeding pipe 99 is provided in a rear part and on an uppersurface of the second tank main body 98. A second feeding port 113 isopened upward. A cap 125 openably closing the second feeding port 113 isprovided in an upper end of the second feeding pipe 99. In a case ofthis fifth embodiment, by opening a front panel 135, a urea aqueoussolution can be fed to the urea aqueous solution tank 94 from aninterior of the cabin 3. Fuel is fed to a fuel tank 83 from the leftside of the machine body 2 which is the outer side of the machine body2. Thereby, a confusion of feeding of the urea aqueous solution withfeeding of the fuel can be prevented. In addition, the urea aqueoussolution tank 94 is provided near the front panel 135. Thus, when thefront panel 135 is opened, the urea aqueous solution can be fedimmediately. The other configurations are the same as those of thesecond embodiment.

Sixth Embodiment

FIGS. 27 and 28 show a sixth embodiment. Elements having substantiallythe same function as those in the second to fifth embodiments will benumbered the same here, and will not be described and/or illustratedagain in detail here for the sake of brevity.

In the sixth embodiment, a second tank main body 98 is provided in amachine body 2 on the lower side of a left part of a step 114. A secondfeeding pipe 99 does not have the second extension pipe 122 described inthe second embodiment. Therefore, this second feeding pipe 99 is formedby a single pipe member.

The second feeding pipe 99 is provided in a rear part and on an uppersurface of the second tank main body 98. A second feeding port 113 isopened upward. A cap 125 openably closing the second feeding port 113 isprovided in an upper end of the second feeding pipe 99. A through hole128 is formed in the left part of the step 114 which is the partcorresponding to the second feeding pipe 99. Via this through hole 128,an upper part of the second feeding pipe 99 projects toward the upperside of the step 114. Therefore, the second feeding port 113 and the cap125 are positioned in a cabin 3. Also in a case of this sixthembodiment, by opening a front panel 135, a urea aqueous solution can befed to a urea aqueous solution tank 94 from an interior of the cabin 3.Fuel is fed to a fuel tank 83 from the left side of the machine body 2which is the outer side of the machine body 2. Thereby, a confusion offeeding of the urea aqueous solution with feeding of the fuel can beprevented. In addition, the urea aqueous solution tank 94 is providednear the front panel 135. Thus, when the front panel 135 is opened, theurea aqueous solution can be fed immediately. The other configurationsare the same as those of the second embodiment.

In the sixth embodiment, the second tank main body 98 is provided in themachine body 2 on the front side of the engine 73. Alternatively, thesecond tank main body 98 is provided in the machine body 2 on the frontside of the engine 73 and on the rear side of the fuel tank 83.Alternatively, the second tank main body 98 is provided in the machinebody 2 on the front side of the fuel tank 83. Thereby, the second tankmain body 98 that stores a urea aqueous solution is installed in theplace where the temperature environment is favorable. Accordingly,freezing, evaporation, and the like of the urea aqueous solution can besuppressed, and the urea aqueous solution tank 94 can be favorablymounted in the working machine 1 such as a compact track loader and askid steering loader.

In the fifth embodiment and the sixth embodiment, the urea aqueoussolution tank 94 is arranged in the machine body 2 on the front side ofthe vertical plate 116, and no heat sources are provided on the frontside of the vertical plate 116. Thus, the urea aqueous solution tank 94is not easily influenced by the heat sources in the machine body 2 suchas the engine 73 and the hydraulic pumps 78, 79, 80, 81.

The first to sixth embodiments of the present invention are describedabove. The embodiments disclosed herein are thought to be notrestriction but examples in all aspects. The scope of the presentinvention is indicated not by the above description but by the claims,and is intended to include equivalent meanings to the claims and allmodifications within the scope.

For example, as shown in FIGS. 30 and 31, the embodiments of the presentinvention may be adopted as a working machine 1 having neither liftlinks 60 nor control links 61. A working machine 1 shown in FIG. 30 hasboom support portions 136 extending upward in rear parts of an innerwall 18 and an outer wall 19. A rear part of a boom 58 is arrangedbetween the boom support portions 136. The rear part of the boom 58 issupported on the boom support portions 136 rotatably about the lateralaxis by a first pivot shaft 66. A boom cylinder 62 is arranged sidewisein such a manner that one end faces the front side and the other endfaces the rear side. A cylinder tube 68 of the boom cylinder 62 isprovided between the inner wall 18 and the outer wall 19. Therefore, theinner wall 18 is provided on the side of the boom cylinder 62 which isthe machine body inner side. The outer wall 19 is provided on the sideof the boom cylinder 62 which is the machine body outer side (on theside opposite to the inner wall 18). The one end of the boom cylinder 62is supported on an intermediate part of the boom 58 pivotably rotatablyabout the lateral axis by a third pivot shaft 69. The other end of theboom cylinder 62 is supported between the inner wall 18 and the outerwall 19 pivotably rotatably about the lateral axis by a fourth pivotaxis 70.

The other configurations are the same as the above embodiments.

A point of a working machine 1 shown in FIG. 31 different from theworking machine 1 shown in FIG. 30 is as follows.

A pivotably supporting portion 137 is provided in an upper part on thefront edge side of an outer wall 19. Between this pivotably supportingportion 137 and an inner wall 18, the other end of a boom cylinder 62 issupported pivotably rotatably about the lateral axis by a fourth pivotshaft 70.

FIG. 32 shows a working machine 1 according to further variation of theembodiments. In this working machine 1, a radiator 74 is provided on theupper side of an engine 73. Between the radiator 74 and the engine 73, acooling fan 76 driven by an electric motor, a hydraulic motor, or thelike is provided. This cooling fan 76 also generates cooling wind towardthe radiator 74. The cooling wind passing through the radiator 74 isdischarged for example to the upper side of a machine body 2.

As shown in FIG. 33, in the further variation of the embodiments, nocut-away portion 26 is provided in an inner wall 18, and a machine bodyinner part of a urea aqueous solution tank 94 is covered by the innerwall 18. However, a hole for letting a hose connecting a supply portion101 of the urea aqueous solution tank 94 and a SCR pump 95 pass throughis provided. In this variation, a place surrounded by the inner wall 18,an outer wall 19, a rear wall 22, and a partition wall 22 serves as aninstallment portion 97. In other words, in this variation, a placesurrounding four sides of the urea aqueous solution tank 94 includingthe front side, the rear side, the machine inner side, and the machineouter side serves as the installment portion 97.

It should be noted that as shown in FIG. 32, also in the working machine1 according to the further variation in which the radiator 74 isprovided on the upper side of the engine 73, an installment portion 97may also be formed by an outer wall 19, a rear wall 21, and a partitionwall 22 as shown in FIG. 4. In other words, a place surrounding threesides of a urea aqueous solution tank 94 including the front side, therear side, and the machine body outer side may serve as the installmentportion 97.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed is:
 1. A working machine comprising: a machine bodyhaving a front and a rear opposite to the front in a front-reardirection of the working machine and having a right side and a left sideopposite to the right side in a right-left direction perpendicular tothe front-rear direction; a right traveling device arranged on the rightside of the machine body; a left traveling device arranged on the leftside of the machine body; a boom having a boom front and a boom rearopposite to the boom front in the front-rear direction, the boom rearbeing rotatably supported at the rear of the machine body, the boomfront being to be connected to a working tool; an engine mounted in themachine body; a selective catalytic reduction catalyst provided in themachine body and connected to the engine; and a urea aqueous solutiontank to store a urea aqueous solution, the urea aqueous solution tankbeing connected to the selective catalytic reduction catalyst andprovided in the machine body between the engine and the front of themachine body in the front-rear direction.
 2. The working machineaccording to claim 1, wherein the urea aqueous solution tank is providedon either side of the right side and the left side in the right-leftdirection.
 3. The working machine according to claim 1, wherein theengine has an output shaft which is provided along the front-reardirection.
 4. The working machine according to claim 1, furthercomprising: a traveling device support body supporting the righttraveling device and the left traveling device, wherein the machine bodydoes not rotate with respect to the traveling device support body. 5.The working machine according to claim 1, further comprising: a cabinmounted in the machine body between the right side and the left side inthe right-left direction and between the engine and the front of themachine body in the front-rear direction.
 6. The working machineaccording to claim 1, further comprising: a hydraulic pump configured tobe driven by the engine, the urea aqueous solution tank being providedbetween the hydraulic pump and the front of the machine body in thefront-rear direction.
 7. The working machine according to claim 6,wherein the hydraulic pump is provided between the engine and the frontof the machine body in the front-rear direction.
 8. The working machineaccording to claim 7, wherein the engine has an output shaft, andwherein the hydraulic pump has a shaft to be driven by the output shaftof the engine and is provided such that the shaft of the hydraulic pumpis substantially coaxial with the output shaft of the engine.
 9. Theworking machine according to claim 8, wherein the engine is providedsuch that the output shaft of the engine is provided in the front-reardirection.
 10. The working machine according to claim 2, furthercomprising: a feeding port via which the urea aqueous solution issupplied to the urea aqueous solution tank, the feeding port beingprovided on the either side of the machine body.
 11. The working machineaccording to claim 10, wherein the feeding port is provided between theboom and one of the right traveling device and the left traveling devicein a height direction of the working machine, the height direction beingperpendicular to the front-rear direction and to the right-leftdirection.
 12. The working machine according to claim 1, furthercomprising: an additional boom having an additional boom front and anadditional boom rear opposite to the additional boom front in thefront-rear direction, the additional boom rear being rotatably supportedat the rear of the machine body, the additional boom front being to beconnected to the working tool, the boom being provided at one of theright side and the left side of the machine body, the additional boombeing provided at another of the right side and the left side of themachine body, the urea aqueous solution tank being provided between theboom and the additional boom in the right-left direction.
 13. Theworking machine according to claim 12, wherein the urea aqueous solutiontank is provided between the boom and the additional boom in theright-left direction when the boom is positioned such that the workingtool is positioned on ground.
 14. The working machine according to claim5, wherein the urea aqueous solution tank is provided below the cabin ina height direction of the working machine, the height direction beingperpendicular to the front-rear direction and to the right-leftdirection.
 15. The working machine according to claim 14, wherein theurea aqueous solution tank overlaps with the cabin as viewed in theheight direction.
 16. The working machine according to claim 7, furthercomprising: a hydraulic motor provided between a rear end of the engineand the front of the machine body in the front-rear direction to bedriven by the hydraulic pump, the hydraulic motor having a rotationalcenter axis, the urea aqueous solution tank being provided between therotational center axis of the hydraulic motor and the front of themachine body in the front-rear direction.
 17. The working machineaccording to claim 16, wherein the hydraulic motor is configured todrive at least one of the right traveling device or the left travelingdevice.
 18. The working machine according to claim 7, furthercomprising: a feeding port via which the urea aqueous solution issupplied to the urea aqueous solution tank, the feeding port beingprovided on either side of the right side and the left side of themachine body in the right-left direction; and a hydraulic motor providedbetween a rear end of the engine and the front of the machine body inthe front-rear direction to be driven by the hydraulic pump, thehydraulic motor having a rotational center axis, the feeding port beingprovided between the rotational center axis of the hydraulic motor andthe front of the machine body in the front-rear direction.